Expected Results

If network has DHCP server running, you should get an IP Address, Default Route (gateway) and DNS addresses automatically. Check this via "Network Settings" in Gnome or "Network Management" applet in KDE and in terminal by running commands: ip address, ip route and ip -6 route. If network supports IPv6 autoconfiguration via DHCPv6 or SLAAC your interface should have two IPv6 addresses: First local-link starting with "fe80::" and second globally unique address provided by network. Ping(s) should be answered.

When interface is disabled, check by running ip address if interface state is "DOWN" and doesn't have other IP addresses then local-link. Run ip route and ip -6 route and check if all routes from disabled network are removed. After enabling, interface should return to previous state. Ping(s) should be answered.

Interface should be configured properly, check with ip address, ip route and ip -6 route. Ping(s) should be answered.

Optional

Test various IPv4 and IPv6 configuration options, correct and even incorrect. Check how Network Manager handles this configurations and if it behaves as you expect.

Test "802.1x Security", if you have an infrastructure or you are able to setup it.